US citizen on 1099 working in India

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I have been offered to work as an independent contractor for 6 months in my company. My company will pay me in USD and I will be on 1099. Currenlty I am Indian citizen, but am in the process of getting US citizenship.
I have an option to work here or India and I am planning to stay in India for maybe 5 out of 6 months. contract will be from jan-jun 2013. I will end up staying in India after that, means will be in india for more than 180 days.
I have several questions.

a. Since I will become US citizen, what kind of visa do I need to go to India.
b. Lets say I get business visa, from tax point of view can I just file US taxes.
c. Is it possible to go to India on entry visa and work. I am thinking that since I will not get paid in India it may be OK.
d. Will I have to declare this on my Indian taxes?

Thanks in advance.